As a result of central nervous system involvement or treatment, many survivors of childhood cancer suffer from significant attentional deficits. The proposed project will investigate the efficacy of a multi-modal Cognitive Remediation Program (CRP) specifically designed to improve survivors attentional deficits which occurred, presumably, as a consequence of cancer and its treatment. For this study, survivors are further defined as having been treated or prophylaxed for a central nervous system cancer (leukemia, brain tumor, non-Hodgkin's lymphoma). A randomized design will be used to evaluate the effectiveness of a 4-to-5 month CRP on attention and other cognitive skills in school-aged children/adolescents 6 to 17 years of age. The stability of achieved change will be evaluated six months later. Childhood cancer survivors who are at least one year off treatment will be screened for an attentional deficit and if it is detected, they will be randomized to receive CRP (n=112) or no treatment (n=56). CRP consists of 20 two-hour sessions of attention training. Subjects will be evaluated pre-treatment, post-treatment (or at a 5 month interval for the control subjects), and for the treatment group at six-month follow-up. Measures of focused attention, working memory, memory recall, learning, vigilance, academic achievement, school behavior, and self-esteem will be administered. Statistical analyses will assess individual and group changes in attention and other cognitive skills, and these changes will be related to changes in academic achievement, school behavior, and self-esteem. To evaluate the mothers' role in influencing the child's compliance with CRP, they will be evaluated pre-treatment with measures of problem-solving skills, parenting skills, and emotional stability. Secondary and exploratory analyses will examine the influences of maternal factors on CRP adherence and effectiveness.